I asked him, why would a Hmong (Originally from the warmer part of the world), choose to live in Minnesota (not so warm in winter..), but we could not really understand each other.

Back online i started to investigate more and was surprised by the history.

Read the Wikipedia article, it gives a very interesting insight in the South East Asian ethnic group and their involvement in the US foreign politics in the area (Vietnam war etc).

Some quotes:

In the early 1960s, the U.S. Central Intelligence Agency (CIA) began to recruit the indigenous Hmong people in Laos to join fighting the Vietnam War, named as a Special Guerrilla Unit led by General Vang Pao. About 60% of the Hmong men in Laos were supported by the CIA to join fighting for the "Secret War" in Laos.[25][26] The CIA used the Special Guerrilla Unit as the counter attack unit to block the Ho Chi Minh Trail, the main military supply route from the north to the south. Hmong soldiers put their lives at risk in the frontline fighting for the United States to block the supply line and to rescue downed American pilots. As a result, the Hmong suffered a very high casualty rate; more than 40,000 Hmong were killed in the frontline, countless men were missing in action, thousands more were injured and disabled.

The Secret War began around the time that the U.S. became officially involved in the Vietnam War. Following the U.S. withdrawal from Vietnam in 1975, the Lao kingdom was overthrown by the communists and the Hmong people became targets of retaliation and persecution. While some Hmong people returned to their villages and attempted to resume life under the new regime, thousands more made the trek to and across the Mekong River into Thailand, often under attack. This marked the beginning of a mass exodus of Hmong people from Laos.

Throughout the Vietnam War, and for two decades following it, the U.S. government stated that there was no "Secret War" in Laos and that the U.S. was not engaged in air or ground combat operations in Laos. In the late 1990s, however, several U.S. conservatives, alleging that the Clinton administration was using the denial of this covert war to justify a repatriation of Thailand-based Hmong war veterans to Laos, urged the U.S. government to acknowledge the existence of the Secret War and to honor the Hmong and U.S. veterans from the war. On May 15, 1997, in a total reversal of U.S. policy, the U.S. government acknowledged that it had supported a prolonged air and ground campaign against the NVA and VietCong.

Plans to resettle additional Hmong refugees in the U.S. have been complicated by provisions of President Bush’s Patriot Act and Real ID Act, under which Hmong veterans of the Secret War, who fought on the side of the United States, are classified as terrorists because of their historical involvement in armed conflict.[48]

Many Hmong/Mong refugees resettled in the United States after the Vietnam War. Beginning in December 1975, the first Hmong/Mong refugees arrived in the U.S., mainly from refugee camps in Thailand; however, only 3,466 were granted asylum at that time under the Indochina Migration and Refugee Assistance Act of 1975. In May 1976, another 11,000 were allowed to enter the United States, and by 1978 some 30,000 Hmong/Mong people had immigrated. This first wave was made up predominantly of men directly associated with General Vang Pao‘s secret army. It was not until the passage of the Refugee Act of 1980 that families were able to enter the U.S., becoming the second wave of Hmong/Mong immigrants. Today, approximately 270,000 Hmong/Mong people reside in the United States, the plurality of whom live in California (65,095 according to the 2000 U.S. census), Minnesota (41,800), and Wisconsin (33,791).